A few patches later, and the game is much better. AI now uses weapons and sprays with more thought, and I can leave my team alone without worrying about them taking a coffee break or blowing each other up. Grenades are still an issue; the AI doesn't appear to comphrehend what flash grenades are for, and will chuck them at the least useful times.
The Echo squad mission are good. Not much variety compared to the USS ones, but enjoyable all the same.